Let thine eyes look right on, And let thine eyelids look straight before thee.
Let your eyes look right on [with fixed purpose], and let your gaze be straight before you.
Focus your eyes straight ahead; keep your gaze on what is in front of you.
Let your eyes look straight ahead, and let your eyelids precede your steps.
Let thy eyes look straight on, and let thy eyelids go before thy steps.